A ladder is used to help people reach places they would not ordinarily be able to reach. Ladders are often used to climb onto roofs of buildings and are used when washing window or painting. In normal use, the bottom portion of the ladder rests on the ground or other surface, and the top end of the ladder typically leans against the building or work surface. The ladder is oriented at an angle which makes it easy for a user to climb up and down the ladder, and also aids in keeping the ladder from slipping.
One problem with ladders, especially when painting or cleaning the exterior of a house, is that there is an amount of instability because the ladder rests on the side of the house with the only contact with the house being a small portion of the siderails of the ladder. When a person on the ladder reaches outside the rails, the center of gravity shifts causing one or both rails may slide along the work surface, thereby damaging the work surface. Accordingly, it will be appreciated that it would be highly desirable to have a ladder that has lateral stability under normal working conditions and resists sliding.
Another problem with typical ladders is that the siderails of the ladder rest on the work surface with a very small contact area which sometimes dents, scrapes, bruises or otherwise defaces the work surface. It is desirable to have a ladder that contacts the work surface with a broad surface area that does not deface the work surface.
With typical ladders, a work surface with a corner presents a problem. The ladder has to be positioned on one of the two surfaces forming the corner to stabilize the ladder, but this makes the other surface difficult to reach. A typical ladder cannot straddle the corners because the rungs would rest against the corner with the siderails void of contact with the two surfaces creating an unstable condition. Accordingly, it will be appreciated that it would be highly desirable to have a ladder that can straddle a corner without losing stability.